Thesis (Ph.D.) -- University of Adelaide, Dept. of Physics, 1974.

This thesis describes a tool called TXSAMC (Transport Cross Sections from Applied Monte Carlo) that produces shielded and homogenized multigroup cross sections for small fast reactor systems. The motivation for this tool comes from a desire to investigate reactor systems that are not characterized well by existing tools. Proper investigation usually requires the use of deterministic codes to characterize the timedependent reactor behavior and to link reactor neutronics codes with thermal-hydraulics and/or other physics codes. Deterministic codes require an accurate set of multigroup cross section libraries. The current process for generating these libraries is time consuming. TXSAMC offers a shorter route for generating these libraries. TXSAMC links three external codes together to create these libraries. The code creates an MCNP (Monte Carlo N-Particle) model of the reactor and calculates the zoneaveraged scalar flux in various tally regions and a core-averaged scalar flux tallied by energy bin. The core-averaged scalar flux provides a weighting function for NJOY. The zone-averaged scalar flux data is used in TRANSX for homogenization and shielding. The code runs NJOY to produce multigroup cross sections that are tabulated by nuclide, temperature and background cross section in MATXS (Material-wise cross section) format. This library is read by TRANSX which, in conjunction with the RZFLUX (Regular Zone-averaged Flux) files, shields the cross sections and homogenizes them. The result is a macroscopic cross section for the cell within the reactor from which the RZFLUX file was written. The cross sections produced by this process have been tested in five different sample problems and have been shown to be reasonably accurate. For reactor cells containing fuel pins, the typical error in the overall fission, nusigf, (n,2n), absorption and total RRD is only a few percent and is often less than one percent. It appears that the error is less for hexagonal lattices than for square lattices. A significant amount of error is associated with threshold reactions like (n,2n) in the sodium coolant. For the square lattice test problems, a reduction in error occurs when smaller tally regions are selected. This reduction was not observed for hexagonal lattice reactors. Overall, the cross sections produced by TXSAMC performed very well.

Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, September 2003. / Thesis advisor(s): David Jenn, Richard Adler. Includes bibliographical references (p. 65). Also available online.

Thesis--Wisconsin. / Vita. Includes bibliographical references (leaf 64).

iii, 135 leaves : ill. ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics, 1974

Thesis (M.Sc.) - University of the Western Cape, 2008. / Bibliography: leaves 97-101.

This is a report of the second in a projected series of experiments at North Texas State College designed for obtaining information about the microwave scattering properties of various shaped objects.

Approved for public release; distribution is unlimited / The significance of the Radar Cross Section (RCS) in the outcome of military engagements makes its prediction an important problem in modern Electronic Warfare. The POFACETS program, previously developed at the Naval Postgraduate School (NPS), uses the Physical Optics method to predict the RCS of complex targets, which are modeled with the use of triangular facets. The program has minimum computer resource requirements and provides convenient run-times. This thesis upgraded, enhanced and expanded the functionalities and capabilities of the POFACETS program. The new functionalities were implemented by upgrading the Graphical User Interface and model database, allowing the creation of models with an unlimited number of facets, providing capabilities for the automatic creation of models with standard geometric shapes, allowing the combination of existing target models, providing capabilities for sharing target models with commercial CAD programs, and creating new display formats for RCS results. The new computational capabilities include the development of a user- updateable database of materials and coatings that can be applied to models in one or multiple layers, and the computation of their effects on the models' RCS. Also implemented are the computations of the ground's effect on the RCS, and the exploitation of symmetry planes in models, in order to decrease run-time for RCS prediction. / Major, Hellenic Air Force

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